Help with Cam Selection For my 94 Z71 Build

[xx94Z71xx]

Great ill check that out! where you happy with your cam choice? i definatly plan on tuning it but just wana be able to run the stock program to be able to drive it. ill tune it as i go.

 

[PlayingWithTBI]

Yes, I like the cam, I would have gone stiffer but I still have to pass emissions here in AZ. You'll be able to run with your stock chip but you'll probably run lean @ WOT and high rpms. I changed the governor weights in my 700r4 to shift @ 5k. I'm running an ACDelco ADO-EP381 155lph in tank fuel pump from a vortec engine with an 18LB spring in my modified 46mm TB (from https://www.ebay.com/str/sprperformance). That is giving me about 78LBS/HR on the stock 5235206 61LB/HR injectors. In my data logs I'm good so far...

 

[Supercharged111]

That Lunati is similar to the cam I had in my 289, a Clevite identical twin to the Edelbrock Performer cam. Good power all the way through but was DONE at 5200 without swirl port heads.

 

[PlayingWithTBI]

That Lunati is similar to the cam I had in my 289, a Clevite identical twin to the Edelbrock Performer cam. Good power all the way through but was DONE at 5200 without swirl port heads.

That's right on, mine is topped out over 5K with Summit Racing 162108 170cc TBI heads, which flow better than the Vortecs (the swirl ports are junk). I tow a trailer from time to time and, with a stiffer cam, which requires a higher stall torque converter, will overheat the tranny. I'm thinking of going to a 2400rpm stall converter because It's still a dog off the line even with a very aggressive spark table but...

 

[David Barry]

Ok guys, just want to throw this out to you for some productive feedback for one who is new to engine performance.

The two cams I put forth to my mechanic before he started convincing me not to upgrade the cam are the comp cam 12-249-4 vs. the comp cam 12-288-4. I just received the 12-249-4 delivery from Summit. According to Comp Cam, Jegs & Summit Techs the two are very similar. My mechanic immediately pointed out the grind #s. Should I eventually decide to have the cam installed, is this grind # something I should be zeroing in on? Is the Lunati 10120100LK very similar?

 

[PlayingWithTBI]

Just from looking at that cam on http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=90&sb=2 it should have a smooth idle and give you good torque. I personally like the Lunati Voodoo cams but, that's a personal thing. One thing to remember with flat tappet cams - BREAK IN IS CRITICAL!!! You need to use lots of assembly lube, https://www.summitracing.com/parts/rpo-01335 if your cam didn't come with any grease, add ZDDP to your oil https://www.summitracing.com/parts/isk-zddp and follow the manufacturer's recommendations to the tee. After break in and about 2K miles I'll switch to Mobil 1 15-50 or 0-40, depending on your climate - they both have high zinc and phosphorus https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf racing oil with really high properties can plug your cat. I've never had problems with my cats or cams using the others...

HTH

 

[L31MaxExpress]

That's right on, mine is topped out over 5K with Summit Racing 162108 170cc TBI heads, which flow better than the Vortecs (the swirl ports are junk). I tow a trailer from time to time and, with a stiffer cam, which requires a higher stall torque converter, will overheat the tranny. I'm thinking of going to a 2400rpm stall converter because It's still a dog off the line even with a very aggressive spark table but...

I don't see how you are overheating the trans. I tow with a 2,700 and my trans temps stay very cool. I have the factory in radiator cooler with a large external cooler with a thermostatically controlled pusher fan in front. Also have the thermal bypass plumbed in between the radiator cooler and the auxiliary cooler. My trans temps stay in the 160-180°F range year round. Without the bypass they would oftem drop down under 120°F at 75 mph on the highway. Even with the small factory GM cooler the temps stayed under 210°F. I tow a 6,000 lbs 24' travel trailer that is 8' wide and 11' tall. Just adjust the tune to keep the converter locked as much as possible once you are rolling and downshift for the power you need.

 

[PlayingWithTBI]

I didn't say I was overheating, I haven't changed the torque converter yet. I did talk to tech support @ Hughes Performance and they were reluctant to recommend anything over 1,800 stall. If you look at Summit Racing's website and search for a truck torque converter in a 700r4 tranny, you won't see any over 1,800. That's why I'm reluctant. Plus, I live in AZ where ave high in July is over 100 degrees.

What stall are you using and in what tranny?

 

[Supercharged111]

Same as me, 2000 or better. Stock BU82 I think? Small block 4L80 torque converter. Where it stalls depends on how much juice you make.

 

[PlayingWithTBI]

Thanks for the help. I understand about stall speeds related to torque, I was hoping to get it up to ~2,400 because of my power band. As L31 suggested I can always go in to my bin file and play with the TCC settings. Maybe I'll try it some day...